March Audio HPA1

[restorer-john]

I'm no mathematician, but doesn't "almost ∞" = ∞ ?

It makes light-speed:

Probably can do the Kessel Run in <12 parsecs too.

 

[rebbiputzmaker]

Making ridiculous and unsupported claims about the stuff he's peddling, same as my problem with other audio quacks.

You do not find any difference in various types of attenuation? Have you built and tested lightspeed attenuators and measured the distortion component? Any thoughts as how that might affect the sonics? Do all attenuators sound the same? I have experience differences. YMMV

 

[rebbiputzmaker]

It makes light-speed:
View attachment 70595

Probably can do the Kessel Run in <12 parsecs too.

He also put it out for free so where is the harm? LDRs have been used by manufacturers before, it is not the worst thing in the world and they do adjust the volume.

 

[SIY]

You do not find any difference in various types of attenuation?

Where did I say that? Quite the opposite, the LDR stuff is a measurably inferior way to control volume. But it's more expensive, works poorly, and solves non-existent problems. You know, quackery.

 

[rebbiputzmaker]

Where did I say that? Quite the opposite, the LDR stuff is a measurably inferior way to control volume. But it's more expensive, works poorly, and solves non-existent problems. You know, quackery.

Well it’s all depends on one’s perspective. Actually relatively cheap to build, sounds good imo, and many others. In a former life you actually were active on DIY. Your perspective seems to have changed. since then which is fine but there are much worse things out here than that volume control. Ymmv

 

[SIY]

Well it’s all depends on one’s perspective. Actually relatively cheap to build, sounds good imo, and many others. In a former life you actually were active on DIY. Your perspective seems to have changed. since then which is fine but there are much worse things out here than that volume control. Ymmv

Yes, quacks have advocates. And poor designs have fanboys, as we observe here regularly.

 

[restorer-john]

Quite the opposite, the LDR stuff is a measurably inferior way to control volume. But it's more expensive, works poorly, and solves non-existent problems.

I remember buying an ORP-12 (or equiv) LDR when I was about 10 years old and making a light activated switch. It was a beautiful metal encased thing with a clear lens over the element. I thought it was a magical device. 1 Meg to a few hundred ohms in bright light. It even made an appearance in a "modified" Theremin in a science competition.

 

[JohnYang1997]

Well at this point, why not make two switching leds with two photosensitive trasistors. Then change the distance to change the volume. Or use some cloth to block the light. Then tune the sound by changing material of the blocker, metal, toilet paper, silk, wood. You name it. I'm sure we'll reach audio nirvana by doing so.
Oh yes. Why using leds. Just use incandescent light directly. That warm sound with a little roll off. UwU.

 

[SIY]

I remember buying an ORP-12 (or equiv) LDR when I was about 10 years old and making a light activated switch. It was a beautiful metal encased thing with a clear lens over the element. I thought it was a magical device. 1 Meg to a few hundred ohms in bright light. It even made an appearance in a "modified" Theremin in a science competition.

Ditto, I had one that was included in my Philips Electronic Experimenter's Kit I got for my 11th birthday. It wasn't fancy-looking, but it was useful in several of the sensing projects.

 

[rebbiputzmaker]

Yes, quacks have advocates. And poor designs have fanboys, as we observe here regularly.

Do you place your diy tube efforts in the category of poor design?

 

[JohnYang1997]

Do you place your diy tube efforts in the category of poor design?

I've made circuit with tube with 0.00005% thd. So come on. Tube can measure well.

 

[SIY]

Do you place your diy tube efforts in the category of poor design?

The measurements speak for themselves.

And, of course, I don't sell them, or boards, or parts, or anything else other than magazine articles.

 

[restorer-john]

I had one that was included in my Philips Electronic Experimenter's Kit

There were mustard caps in your kit set? Several years ago, I dug out a box full of ancient NOS mustard caps and took advantage of the guitar amp muso's desire for those things. To be fair, they were incredibly close in tolerance and value, with dates from the late 60s/ early 70s.

 

[March Audio]

I remember buying an ORP-12 (or equiv) LDR when I was about 10 years old and making a light activated switch. It was a beautiful metal encased thing with a clear lens over the element. I thought it was a magical device. 1 Meg to a few hundred ohms in bright light. It even made an appearance in a "modified" Theremin in a science competition.

I remember when I was a kid my Tandy (UK name for Radio Shack) electronics kits with those. Loved the crystal earpiece that looked like a hearing aid.

 

[SIY]

There were mustard caps in your kit set? Several years ago, I dug out a box full of ancient NOS mustard caps and took advantage of the guitar amp muso's desire for those things. To be fair, they were incredibly close in tolerance and value, with dates from the late 60s/ early 70s.

And 55 years later, I still remember the two transistors that came with the kit: AC126 and AF116. Sadly, the AF116 had a lead break off, replacements were expensive, and I moved on to learning to scratch-build.

 

[restorer-john]

I remember when I was a kid my Tandy (UK name for Radio Shack) electronics kits with those.

Do you know, I found the 150 in 1 kit set I always wanted, but never asked Santa for, at an op-shop for a few dollars, only a few years ago? It's here, mint if you want to see a pic or two.

 

[March Audio]

Do you know, I found the 150 in 1 kit set I always wanted, but never asked Santa for, at an op-shop for a few dollars, only a few years ago? It's here, mint if you want to see a pic or two.

Oh cool, lots of memories connecting stuff together with those spring terminals.

Was it called Tandy here in Oz?

 

[restorer-john]

And 55 years later, I still remember the two transistors that came with the kit: AC126 and AF116. Sadly, the AF116 had a lead break off, replacements were expensive, and I moved on to learning to scratch-build.

OK, I'm going to see if there's a full legged AF-116 in my germanium bag. Tin whiskers notwithstanding, if there is, it's yours.

 

[SIY]

OK, I'm going to see if there's a full legged AF-116 in my germanium bag. Tin whiskers notwithstanding, if there is, it's yours.

LOL. look for the fourth leg.

I wonder how many thousands of us got our start in electronics with kits like that. Can that sort of thing even be sold today?

 

[restorer-john]

Was it called Tandy here in Oz?

Absolutely. I worked for and managed Tandy Electronics in Southport Qld for several years from 1987 to 1990/1. Intertan was the company (Barrie Canada) covered the international operations of TC (Tandy Corp).

At that point, there were 9000 stores worldwide.

Some of the best times of my life to be honest. The annual conferences were hang-the-expense.